This invention relates to a keyboard musical instrument equipped with key sensors and, more particularly, to a jig for aligning a shutter plate with a key and an assembling method using the jig.
Various kinds of keyboard musical instrument are sold in the market. An automatic player piano is categorized in the keyboard musical instrument. The automatic player piano is an acoustic piano equipped with a playback system and a recording system. The playback system includes solenoid-operated key actuators and a controller. The solenoid-operated key actuators are provided on the key bed under the keyboard, and the controller sequentially energizes the solenoid-operated key actuators for moving the keys without fingering. The keys are moved as if a pianist plays a tune on the keyboard. On the other hand, the recording system includes a data processor and key sensors attached to the white keys and the black keys. While a pianist is fingering on the keyboard, the white/black keys are selectively moved for actuating associated action mechanisms. The action mechanisms give rise to rotation of hammers, and the hammers strike associated music strings. The key sensors are provided on the trajectories of the white/black keys, and notify the key motions to the data processor. The data processor analyzes the pieces of positional data information for the key velocity and timings, and produces music data codes representative of the performance on the keyboard.
A known key sensor is a combination of a shutter plate and photo-couplers. The shutter plate is attached to a lower surface of the associated white/black key, and downwardly projects therefrom. Thus, the shutter plate is movable together with the white/black key. On the other hand, the photo-couplers are provided on the key bed, and radiate light beams across the trajectory of the shutter plate. While a pianist is depressing the white/black key from the rest position toward the end position, the shutter plate sequentially interrupts the light beams. The photo-couplers notify the interruptions to the data processor. The data processor determines lapse of time from the initiation of the performance to the interruption of the light beam, and calculates the key velocity on the basis of the time period between the interruption of the upper light beam and the interruption of the lower light beam. Thus, the key sensors are important parts of the automatic player piano, and the manufacturer assembles the shutter plates and the photo-couplers with the keys and the key bed, respectively.
Conventionally, the shutter plates are manually attached to the white/black keys. If a shutter plate is offset from the target position, the shutter plate does not interrupt the light beams. For this reason, the assembling worker is expected to carefully assembly the shutter plates to the white/black keys. Such a careful work consumes a large amount of time and labor, and increases the production cost of the automatic player piano.
In order to speed up the assembling work, a jig is proposed in Japanese Patent Publication of Unexamined Application (laid-open) No. 3-154097. The prior art jig disclosed in the Japanese Patent Publication of Unexamined Application includes a spacer and an adhesive double coated tape. The photo-couplers are fixed to a cubic case, and a slit is formed in the cubic case. The cubic case is associated with one of the keys. Plural cubic cases are arrayed, and the case array is to be mounted on the key bed. The slit is open to the upper surface of each cubic case, and downwardly penetrates from the upper surface. A pair of photo-couplers is fixed inside the cubic case in such a manner as to radiate the light beams across the slit. The slit is wider than the shutter plate, and the shutter plate is insertable into the slit.
The prior art jig has a base plate to be placed on the upper surface of the cubic case and a vertical plate snugly received in the slit of the cubic case. A narrow slit is formed in the vertical plate, and is open to the upper surface of the base plate. The narrow slit is as wide as the shutter plate. The key sensor is assembled as follows. The array of cubic cases is mounted on the key bed, and the cubit cases are roughly aligned with the associated keys. The prior art jig is placed on one of the cubic cases, and the vertical plate is snugly inserted into the slit formed in the cubic case. The shutter plate is placed on the prior art jig, and is snugly received in the slit formed in the vertical plate. A piece of the adhesive double coated tape is adhered to the upper surface of the shutter plate. The associated key is downwardly moved, and the piece of double coated tape is adhered to the lower surface of the associated key. The shutter plate is fixed to the associated key by means of nails. The above-described assembling work is repeated for all the keys.
The prior art jig makes the shutter plate exactly aligned with the associated key, and permits the manufacturer to complete the assembling work speedy. However, the prior art jig is used for the alignment of each shutter plate with the associated key. This means that the manufacturer needs to move the prior art jig from one cubic case to another. For this reason, the assembling work still consumes a large amount of time and labor, and the production cost is not so widely reduced.
It is therefore an important object of the present invention to provide a jig, which concurrently aligns plural shutter plates with associated keys.
It is also an important object of the present invention to provide an assembling method using the jig.
In accordance with one aspect of the present invention, there is provided a jig for aligning plural shutter members with associated sensors and associated manipulators comprising a shutter guide formed with plural hollow spaces snugly receiving the shutter members, respectively, and having a positioning means for locating the plural hollow spaces at target positions with respect to the associated sensors, and temporal tacking means provided on the plural shutter members for temporality tacking the plural shutter members to the associated manipulators.
In accordance with another aspect of the present invention, there is provided a method for assembling a detector array and shutter members with a keyboard musical instrument having a stationary member and plural manipulators movable with respect to the stationary member comprising the steps of a) preparing a jig having a shutter guide and temporal tacking means, b) mounting the detector array on the stationary member, c) aligning the shutter members with the detectors of the array by using the shutter guide, d) temporality tacking the shutter members to the plural manipulators by using the temporal tacking means for aligning the shutter members with the plural manipulators, and e) fixing the shutter members to the plural manipulators, respectively.